Orthodontic brackets are typically small, slotted devices for use during orthodontic treatment. The brackets are usually configured for attachment to the front surfaces of teeth, either by directly cementing the bracket to a tooth surface or by bonding the bracket to a metal band that encircles the tooth, though they also may be attached to the back surfaces of teeth. The slots in the brackets, which may be referred to as archwire slots or archwire passages, are disposed horizontally or generally horizontally and are configured to receive an archwire. Traditionally, an archwire is a resilient, curved piece of wire that may be bent or twisted prior to installation in the bracket slots, with an archwire typically extending through the slots of all of the orthodontic brackets that are attached to a patient's upper or lower teeth. The engagement between the archwire and the brackets create corrective, or prescriptive, forces that are directed to the teeth by the orthodontic brackets to urge the teeth into a correct or desired alignment or occlusion.
The archwire may be secured in the bracket slots by a variety of mechanisms, such as depending on the bracket configuration. For example, a “ligating” bracket typically requires a separate fastener, such as a ligature wire or elastic band, which is tied or otherwise positioned around ligating structures, such as tie wings, on the bracket body to secure the archwire in place. A “self-ligating” bracket, on the other hand, typically includes a clamp, gate, or other self-locking mechanism, such as a closeable bracket slot, that allows such a bracket to retain the archwire without requiring the use of ligatures or other separate fasteners.
Expressed in slightly different terms, a conventional ligating bracket defines an archwire slot with an opening (typically extending in a plane generally parallel to the base of the bracket and/or surface of the corresponding tooth to which the bracket is secured) into which the archwire may be inserted into the slot (other than by axially inserting the archwire through the opposed ends of the archwire slot), with the opening requiring a ligature or other structure that is not part of the bracket to obstruct or otherwise close the opening to prevent removal of the archwire therethrough. In contrast, a conventional self-ligating bracket defines an archwire slot (such as may be similar or identical to the above-discussed archwire slot of a conventional bracket), but also includes a movable gate or closure. The gate, or closure, is coupled to the body of the bracket and is configured to be slid, pivoted, or otherwise moved from an open position, in which an archwire may be inserted into the archwire passage through the opening, to a closed position, in which the opening of the archwire passage is closed or otherwise obstructed to prevent removal of the archwire therethrough.
Illustrative, non-exclusive examples of ligating orthodontic brackets are disclosed in U.S. Pat. Nos. 6,302,688, 6,582,226, 4,597,739, 4,878,840, 3,772,787, 4,248,588, 4,492,573, 4,614,497, 4,698,017, 1,280,628, 1,821,171, and 3,435,527, the complete disclosures of which are hereby incorporated by reference. Illustrative, non-exclusive examples of self-ligating orthodontic brackets are disclosed in U.S. Pat. Nos. 6,659,766, 6,655,957, 6,358,045, 6,193,508, 5,857,850, 5,711,666, 5,562,444, 5,322,435, 5,094,614, 4,559,012, 4,531,911, 4,492,573, 4,419,078, 4,371,337, 4,077,126, 4,144,642, 4,248,588, 4,698,017, 3,772,787, 4,559,012, 4,561,844, 4,655,708, 4,077,126, 4,419,078, 4,197,642, 4,712,999, and 4,171,568, the complete disclosures of which are hereby incorporated by reference. Still further additional examples of orthodontic brackets are disclosed in U.S. Pat. Nos. 7,819,660, 7,771,640, and 6,632,088, the complete disclosures of which are hereby incorporated by reference. The structures, features, applications, and methods of the above-identified references may be utilized with and/or incorporated into orthodontic appliance systems according to the present disclosure to the extent that doing so does not conflict with the express provisions of the instant disclosure.